Originally called the Palazzo della Signoria, after the Signoria of Florence, the ruling body of the Republic of Florence, it was also given several other names: Palazzo del Popolo, Palazzo dei Priori, and Palazzo Ducale, in accordance with the varying use of the palace during its long history. The building acquired its current name when the Medici duke's residence was moved across the Arno to the Palazzo Pitti.

In 1299,[1] the commune and people of Florence decided to build a palace, worthy of the city's importance and giving greater security, in times of turbulence, to the magistrates. Arnolfo di Cambio, the architect of the Duomo and the Santa Croce church, began constructing it upon the ruins of Palazzo dei Fanti and Palazzo dell'Esecutore di Giustizia, once owned by the Uberti family. Giovanni Villani (1276–1348) wrote in his Nuova Cronica that the Uberti were "rebels of Florence and Ghibellines", stating that the plaza was built so that the Uberti family homes would never be rebuilt on the same location.[1] Giovanni Villani wrote that Arnolfo di Cambio incorporated the ancient tower of the Foraboschi family (the tower then known as "La Vacca" or "The Cow") as the substructure of the tower into its facade;[1] this is why the rectangular tower (height 94 m) is not directly centered in the building. This tower contains two small cells, that, at different times, imprisoned Cosimo de' Medici (the Elder) (1435) and Girolamo Savonarola (1498). The tower is named after its designer Torre d'Arnolfo. The solid cubicle shaped building is enhanced by the simple tower with its clock. The large, one-handed clock was originally constructed in 1353 by the Florentine Nicolò Bernardo, but was replaced in 1667 by a replica made by Georg Lederle from the German town of Augsburg (Italians call him Giorgio Lederle of Augusta) and installed by Vincenzo Viviani.

The cubical building is built in solid rusticated stonework, with two rows of two-lighted Gothic windows, each with a trefoil arch. In the 15th century, Michelozzo Michelozzi added decorative bas-reliefs of the cross and the Florentine lily in the spandrels between the trefoils. The building is crowned with projecting crenellated battlement, supported by small arches and corbels. Under the arches are a repeated series of nine painted coats of arms of the Florentine republic. Some of these arches can be used as embrasures (spiombati) for dropping heated liquids or rocks on invaders.

Duke Cosimo I de' Medici moved his official seat from the Medici palazzo in via Larga to the Palazzo della Signoria in May 1540, signalling the security of Medici power in Florence.[2] The name was officially changed after Cosimo removed to Palazzo Pitti, renaming his former palace the Palazzo Vecchio, the "Old Palace", although the adjacent town square, the Piazza della Signoria, still bears the old name. Cosimo commissioned Giorgio Vasari to build an above-ground walkway, the Vasari corridor, from the palace, through the Uffizi, over the Ponte Vecchio to the Palazzo Pitti.

Cosimo I also moved the seat of government to the Uffizi. The palace gained new importance as the seat of United Italy's provisional government from 1865–71, at a moment when Florence had become the temporary capital of the kingdom of Italy.

Although most of the Palazzo Vecchio is now a museum, it remains the symbol of local government: since 1872 it has housed the office of the mayor of Florence, and it is the seat of the City Council.

The Tower has three bells, the oldest one was cast in the 13th century.

Above the front entrance door, there is a notable ornamental marble frontispiece, dating from 1528. In the middle, flanked by two gilded lions, is the Monogram of Christ, surrounded by a glory, above the text (in Latin): "Rex Regum et Dominus Dominantium" (translation: "King of Kings and Lord of Lords". This text dates from 1851 and does not replace an earlier text by Savonarola[3] as mentioned in guidebooks. Between 1529 and 1851 they were concealed behind a large shield with the grand-ducal coat of arms.

The first courtyard was designed in 1453 by Michelozzo. In the lunettes, high around the courtyard, are crests of the Church and City Guilds. In the center, the porphyry fountain is by Battista del Tadda. The Putto with Dolphin on top of the basin is a copy of the original by Andrea del Verrocchio (1476), now on display on the second floor of the palace. This small statue was originally placed in the garden of the villa of the Medici in Careggi. The water, flowing through the nose of the dolphin, is brought here by pipes from the Boboli Gardens.

This most imposing chamber has a length of 52 m (170 ft) and is 23 m (75 ft) broad. It was built in 1494 by Simone del Pollaiolo, on commission of Savonarola who, replacing the Medici after their exile as the spiritual leader of the Republic, wanted it as a seat of the Grand Council (Consiglio Maggiore) consisting of 500 members. Later the hall was enlarged by Giorgio Vasari so that Grand Duke Cosimo I could hold his court in this chamber. During this transformation famous (but unfinished) works were lost, including the Battle of Cascina by Michelangelo,[4] and the Battle of Anghiari by Leonardo da Vinci. Leonardo was commissioned in 1503 to paint one long wall with a battle scene celebrating a famous Florentine victory. He was always trying new methods and materials and decided to mix wax into his pigments. Leonardo had finished painting part of the wall, but it wasn't drying fast enough, so he brought in braziers stoked with hot coals to try to hurry the process. As others watched in horror, the wax in the fresco melted under the intense heat and the colors ran down the walls to puddle on the floor. Michelangelo never even got past making the preparatory drawings for the fresco he was supposed to paint on the opposite wall—Pope Julius II called him to Rome to paint the Sistine Chapel, and the master's sketches were destroyed by eager young artists who came to study them and took away scraps. The surviving decorations in this hall were made between 1555 and 1572 by Giorgio Vasari and his helpers, among them Livio Agresti from Forlì. They mark the culmination of mannerism and make this hall the showpiece of the palace.

On the walls are large and expansive frescoes that depict battles and military victories by Florence over Pisa and Siena :

The Taking of Siena

The Conquest of Porto Ercole

The Victory of Cosimo I at Marciano in Val di Chiana

Defeat of the Pisans at the Tower of San Vincenzo

Maximillian of Austria Attempts the Conquest of Leghorn

Pisa Attacked by the Florentine Troops

The ceiling consists of 39 panels also constructed and painted by Vasari and his assistants, representing Great Episodes from the life of Cosimo I, the quarters of the city and the city itself and towards the center is the apotheosis : Scene of His Glorification as Grand Duke of Florence and Tuscany

Genio della Vittoria by Michelangelo

On the north side of the hall, illuminated by enormous windows, is the raised stage called the Udienza, built by Bartolommeo Bandinelli for Cosimo I to receive citizens and ambassadors. Above are frescoes of historical events; among these, that of Boniface VIII receiving the ambassadors of foreign States and, seeing that were all Florentines, saying: "You Florentines are the quintessence".

In the niches are sculptures by Bandinelli: in the center the statue of the seated "Leo X" (sculpted assisted by his student Vincenzo de'Rossi), and on the right a statue of "Charles V crowned by Clement VII".

There are also numerous bombastic Medicean tapestries on the walls, including Stories of the Life of St. John the Baptist, taken from the frescoes of Andrea del Sarto.

The six statues along the walls that represent the "Labors of Hercules" are by Vincenzo de'Rossi.

At the end of the hall is situated a small sideroom without windows. This masterpiece, the Studiolo of Francesco I (a studiolo is a small study) was also designed by Vasari in a manneristic style (1570–1575). The walls and the barrel vault are filled with paintings, stucco and sculptures. (Baroque paintings hide secret cupboards.) Most paintings are by the School of Vasari and represent the four elements : water, fire, earth and air. The portrait of Cosimo I and his wife Eleonora of Toledo was made by Bronzino. The delicate bronze sculptures were made by Giambologna and Bartolomeo Ammanati. Dismantled within decades of its construction, it was re-assembled in the 20th century.

The other rooms on the first floor are the Quartieri monumentali. These rooms, the Residence of the Priors and the Quarters of Leo X, are used by the mayor as offices and reception rooms. They are not accessible to the public.

A staircase, designed by Vasari leads to the second floor. This floor contains the Chapel of Signoria, the Hall of Justice ("Sala delle Udienze"), the Room of the Lilies (Sala dei Gigli), the Study Room and the Apartments of the Elements.

These apartments (Sala degli Elementi) consist of five rooms (such as the Room of Ceres) and two loggias. The commission for these rooms was originally given by Cosimo I to Battista del Tasso. But on his death, the decorations were continued by Vasari and his helpers, working for the first time for the Medicis. These rooms were the private quarters of Cosimo I.

The walls in the Room of the Elements are filled with allegorical frescoes Allegories of Water, Fire and Earth and, on the ceiling, represents Saturn.

The original statue "Boy with a Fish" by Verrocchio is on exhibit in one of the smaller rooms (the copy stands on the fountain in the first courtyard).

This room (the Sala di Ercole) gets its name from the subject of the paintings on the ceiling. Also the tapestries show stories of Hercules. The room contains a Madonna and Child and an ebony cabinet called a stipo inlaid with semi-precious stones.

Called the Green Room because of the color of the walls. With decorations on the ceiling by Ridolfo del Ghirlandaio. On the right is the Chapel frescoed by Bronzino (1564) with the Stories of Moses. Also by Bronzino is the large Pietà on the altar. The small door in the room indicates the beginning of the Vasari corridor, a passageway to the Palazzo Pitti built by Vasari for Cosimo I.

It was named because of the ceiling decoration. At one time it was used for the Ladies-in- waiting at the court of Eleonora di Toledo. It contains Portraits of Medici Princes by Sustermans, statues by a Florentine art school and a tapestry by Fevère.

On the ceiling is the Coronation of Esther decorated by Stradano, with an inscription in honor of Eleonora di Toledo. The room contains a lavabo and two tapestries by Van Assel representing Spring and Autumn.

Originally called the '"Room of Gualdrada"' from the subject of the ceiling painting, this room was one of the private rooms of Eleonora of Toledo, wife of Cosimo I de' Medici. The paintings are by the Flemish painter Jan Stradan, better known under his Italian name Stradano. Against the wall is a cabinet with Florentine mosaic designs.

On the portal of the Chapel is an inscription in honor of Christ (1529). The door, communicating with the Hall of Lilies, is a marvel. The marble mouldings of this portal were sculpted by the brothers Giuliano and Benedetto da Maiano. Its inlaid woodwork (intarsia) was carved by Del Francione. They give us portraits of Dante and Petrarch

The large frescoes on the walls, of a decorative value representing Stories of Furius Camillus, by Francesco Salviati, were made in the middle of the 16th century. Since Salviati had his schooling in the circle around Raphael in Rome, these frescoes are mirrored on Roman models and therefore not typical of Florentine art. Furius Camillus was a Roman general, mentioned in the writings of Plutarchus.

A small doorway leads into the adjoining small chapel dedicated to St. Bernard, containing a reliquary of the Saint. Here the priors used to supply divine aid in the execution of their duties. In this chapel, Girolamo Savonarola said his last prayers before he was hanged on the Piazza della Signoria and his body burned.

The marvellous frescoes on the walls and ceiling, on a background imitating gold mosaic, are by Ridolfo Ghirlandaio. Of particular interest are The Holy Trinity on the ceiling and The Annunciation on the wall facing the altar. On the altar was a painting representing the Holy Family by Mariano Graziadei da Pescia, a pupil of Ridolfo Ghirlandaio. It is now on exhibition in the corridor of the Uffizi Gallery. Instead, there is a good painting of St. Bernard by an unknown artist.

Frescoes in the Hall of Lilies

The carved ceiling of the Hall of the Lilies, as this room is usually called, decorated with fleur-de-lys, and the Statue of St. John the Baptist and Putti are all by Benedetto da Maiano and his brother Giuliano. The goldenfleur-de-lys decorations on blue background on the ceiling and three walls refer to the (short-lived) good relations between Florence and the French Crown.

Ceiling with fleur-de-lys

On the wall are frescoes by Domenico Ghirlandaio, painted in 1482. The apotheosis of St. Zenobius, first patron saint of Florence, was painted with a perspectival illusion of the background. In this background one can see the Cathedral, with Giotto's original facade and bell tower. In the lunette above is a bas-relief of the Madonna and Child. This fresco is flanked on both sides by frescoes of famed Romans: on the left Brutus, Gaius Mucius Scaevola and Camillus, and on the right Decius, Scipio and Cicero. Medaillons of Roman emperors fill the spandrils between the sections.

The door in this wall leads to the Stanza della Guardaroba (Hall of Geographical Maps). This door is flanked by two dark marble pillars, originally from a Roman temple.

The Hall of Geographical Maps or Wardrobe is where the Medici Grand Dukes kept their precious belongings. The cabinets and carved ceiling are by Dionigi Nigetti.

The doors of the cabinets were decorated with 53 remarkable maps of scientific interest, oil paintings by the Dominican monk Fra Ignazio Danti (1563–1575), brother of the sculptor Vincenzo Danti, and Stefano Buonsignori (1575–1584). They are of great historical interest and give a good idea of the geographical knowledge in the 16th century. Danti followed the Ptolemaic system, while already using the new cartographical system of Gerardus Mercator.

In the center of the room is the large globe mappa mundi, ruined by excessive restorations.

This was Machiavelli's office when he was Secretary of the Republic. His polychrome bust in terracotta and his portrait are by Santi di Tito. They are probably modelled on his death mask. In the center of the room, on the pedestal is the famous Winged Boy with a Dolphin by Verrocchio, brought to this room from the First Courtyard.

The reassembled room was used by Cellini to restore the treasures of the Medici princes. From the little window in the wall, Cosimo I spied on his ministers and officers, during meetings in the Salone dei Cinquecento. It became a museum of Mannerist paintings.

Located in between the first and second floors, these rooms are occupied by Renaissance and Medieval objects given in a bequest by Charles Loeser, an American expat collector and scholar. This collection is one of the most valuable municipal collections for its artistic and historical value. The rooms are located in the old palace, and were renovated in the mid-15th century by Michelozzo. It is the only part of the palace where the original 14th- and 15th-century ceilings are still entirely visible. Cosimo I's mother Maria Salviati lived in these rooms after Cosimo moved the family from Palazzo Medici to the Palazzo Vecchio (at that point Palazzo Ducale).

The first room holds a Madonna con Bambino e san Giovannino, from the school of Lorenzo di Credi, a Madonna col Bambino in stucco painted in the Florentine school in the 15th century, a Madonna in Adoration by Christ with Saint Giovannino by Jacopo del Sellaio, a Madonna and Child attributed to Master of the Griggs Crucifix (15th century), and a Madonna Enthroned by the Tuscan school of the 1300s. Above the stone steps is a little room that was for a time a studiolo for Cosimo I. The window looks out over Piazza della Signoria and the room is decorated with birds, animals, fishes, and vegetal elements works by Bachiacca.

The dining room holds one of the most famous works of the Loeser Collection, The Portrait of Laura Battiferri (wife of Bartolomeo Ammannati), by famous Renaissance painter Bronzino around 1555. Adjacent is another Mannerist work, The Portrait of Ludovico Martelli, by a follower of Pontormo, possibly Michele Tosini. There is also a small sketch on fresco, Battle of the Knights for Vasari's Defeat of the Pisans at the Tower of Saint Vincent, by a student Giovan Francesco Naldini, which used to be displayed on the balcony above the Salone dei Cinquecento by Vasari's complementary monumental work. By the fireplace are two Romanesque sculptures, a capital with an eagle (first half of the 13th century) and a Coronation Head (first half of 12th century).

In the corner room, three Madonna and Children paintings are on display. The first, Madonna and Child is by the Master of Saints Flora and Lucilla, from the 14th century. The second, Madonna and Child with Saint Little Saint John is a later Renaissance work by Spanish artist Alonso Berruguete from 1514-1518, and the third is Madonna and Child by prominent Sienese artist Pietro Lorenzetti. This room also holds Adoring Angel by Tino di Camaino from around 1321, a Bust of Saint Antonino in painted plaster from the 15th century, and an embroidery designed by Raffaellino del Garbo.